Could you please explain more elaborately on what you are looking for?

I guess for a clinical setting, you would know the SNPs from research papers and also get the primers for them from the same source. The SNP can have three possibilities, AA, AB or BB. So your protocol should be able to tell you, which SNP is present. You could use an ARMS set up, RFLP, or sequencing to figure out what zygosity exists.